The Core is a central resource and integrative force for all aspects of this Program Project. It consists of four interrelated components each of which perform functions key to the operation of the Program and its three projects. These are: 1) Program Administration, 2) Animal Maintenance, 3) Biomarker Assessment, and 4) Biostatistics. The aim of Program Administration is to provide overall fiscal management of the Program Project, including the purchase of equipment and supplies, maintenance of equipment, and to provide administrative support services for manuscript and progress report preparations and renewal grant applications. Dr. Richard Weindruch, the Program Project and Core PI, will direct this portion of the Core and assume overall administrative responsibility for the Program. He will work with the Core's Co-PI, Dr. Ellen Roecker, the biostatistician who has been associated with this study since its utilization of the rhesus monkey cohorts so are to ensure that the Specific Aims of the three Research Projects and of the Biomarker Assessment portion of the Core are met. This will be done by maintaining the highest standards of animal care and sample procurement. The Animal Maintenance section is responsible for appropriate Project or Biomarker laboratories. Dr. Joseph Kemnitz, who has 15 years research experience with rhesus monkeys at the WRPRC and who presently oversees all aspects of animal maintenance for the current DR project, will lead this portion of the Core. To a large extent, the functions associated with animal maintenance and clinical monitoring of the subjects are linked to the third component of the Core which involves Biomarker Assessment. This subunit of the Core includes the collection of data on potential biomarkers of aging to establish parameters and patterns of normal aging in this species. It will also assess the sensitivity of putative biomarkers of aging to the effects of DR in a randomized longitudinal trial in male and female rhesus monkeys. Dr. William Ershler, PI of the currently funded R01 to study DR and its effect on aging in rhesus monkeys, will assume responsibility for the Biomarker section of the Core. The final Core component is Biostatistics. The primary role of the Biostatistics subsection is to help ensure high quality research results by providing statistical input into the design, conduct and analysis of data collected by program investigators. Dr. Roecker, who is Co-PI of the Core, will direct it s Biostatistics section. The fact that the Core is a pivotal and major element of this Program Project is reflected by the P01's budget: 56% of the direct costs requests over the 5 years are to support Core activities.